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In this work, reduced graphene oxide-coated zinc borotellurite doped with erbium oxide nanoparticles denoted as ZBTEr (NPs)-rGO was studied as an approach to enhance the optical properties of glass materials. Herein, a melt-quenched technique was used to prepare the ZBTEr (NPs) glasses. A simple and inexpensive spray-coated technique was employed to deposit the rGO onto the glass surfaces directly. The morphological studies of ZBTEr (NPs)-rGO glass surfaces were investigated by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) meanwhile, the structural investigation of ZBTEr (NPs) glasses was revealed by X-ray diffraction (XRD) and Raman analysis. The morphological analysis revealed the residual oxygen groups functionalized on ZBTEr (NPs)-rGO glass surfaces meanwhile, TEM images confirmed the presence of Er (NPs) in the glassy matrix. The glass samples showed the existence of structural disorder and amorphous nature. The absorption spectra presented the transition bands that existed from 4I15/2 ground state level to excited state levels of 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I11/2, and 4I9/2, respectively. Judd–Ofelt analysis was performed to obtain the intensity parameters (Ωλ), radiative transition (A), branching ratios (βR), and radiative lifetimes (tr). The radiative parameter and branching ratio values suggested the higher stimulated emission radiative at 2H11/2 → 4I15/2 transition for present glass The luminescence spectra exhibited two emission peaks centred at 539 nm and 558 nm which were assigned to 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions, respectively. The optical results for ZBTEr (NPs)-rGO and ZBTEr (NPs)-uncoated were compared to determine the differences between coated and uncoated glasses. These results highlight the significant effect of rGO deposited onto tellurite-based glass and thus, this work proposed the potential coating materials for improving current fiber optics. [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials offer superior properties especially in optical performance. The existence of oxygen functionalized group in graphene active layers is beneficial to enhance the optical properties of current tellurite glass. In this work, two series of glasses denoted as ZBTEr (uncoated) and ZBTEr-GO (coated) were successfully prepared using melt-quenching and low-cost spray coating techniques. X-ray diffraction analysis was done on both glass series and confirmed the amorphous structural arrangement in the glass system. Morphological study was investigated by using Scanning Electron Microscopy (SEM) and revealed the distribution of graphene layers on the glass surface. The UV-Vis spectroscopy was carried out and several absorption bands were determined for both series of glasses. The computation of oxide ion polarizability and optical basicity were investigated based on Lorentz-Lorentz equation. The oxide ion polarizability and optical basicity for ZBTEr-GO (coated) glasses were found higher than ZBTEr (uncoated) glasses due to the existence of sp2 graphitic attached on the oxygenic functional groups in GO layers. The metallization criterion values for ZBTEr-GO (coated) glasses were found decreased and tend to be more metallic. Hence, the deposition of graphene layers on the tellurite glasses offer a new strategy to improve the current telecommunication devices. [ABSTRACT FROM AUTHOR]

The versatility of graphene oxide (GO) as coating materials on the glass surface is a new revolution in the advanced glass era. In this work, GO liquid solution was prepared by using electrochemical exfoliation in an electrolyte solution assisted by different surfactants. Meanwhile, a glass series was prepared by using the conventional meltquenched technique. A low-cost and simple spray deposition technique was used to deposit the GO on the glass sample. The obtained glass series was denoted as GO coated TNd (NPs), meanwhile, the uncoated glass was labelled as uncoated TNd (NPs). The linear optical properties of GO coated TNd (NPs) glass series was determined using UVVis spectrophotometer and utilizing the Lorentz-Lorentz equation to determine the value of polarizability. X-ray diffraction spectra revealed the amorphous structural characteristics of the glass series. The SEM morphological image revealed the variation of GO distribution on the glass surface due to the agglomeration and inhomogeneity of GO distribution on the glass surface. The homogeneity of GO distribution on the glass surface is negligible in this work as we focus solely on the effect of GO on glass properties. According to the observations, the value of GO-coated TNd (NPs) is in the range 3.4531-3.8549 Å and uncoated TNd (NPs) is in the range 2.709-2.774 Å. Meanwhile, the optical basicity value ranges from 1.220 to 1.262. These results demonstrate that the polarizability of oxide ions and optical basicity values of the GO coated TNd (NPs) glass series was higher than the uncoated TNd (NPs) glass. The metallization criterion for the GO-coated TNd (NPs) glass system is in the range of 0.3 < M < 0.4. Based on these results, the obtained glasses are promising in linear optical glass fibre. [ABSTRACT FROM AUTHOR]

Objectives: Our study reports the immunomodulatory potency of Quercus infectoria gall extract in vitro . The aqueous extract was prepared and examined for its effects on cell proliferation, phagocytic activity, nitric oxide (NO) production, and cytokine synthesis by murine macrophages., Methods: Proliferative, phagocytic activity, and NO production of extract-treated and control cells were studied using proliferative assay, flow cytometry, and Griess reaction, respectively. An enzyme-linked immunosorbent assay was performed to determine the levels of pro- and anti-inflammatory cytokines in the macrophage culture., Results: Treated macrophages had a higher proliferative rate and phagocytic activity compared to untreated macrophages. The cell treatment with an extract concentration of 64 μg/mL demonstrated a significant decrease in NO production ( p < 0.001). An increase in cytokine levels (IL-2, IL-5, IL-10, IL-17A, IL-23, TGF-β1) was observed; however, this increase was not statistically significant., Conclusions: Our study suggests that gall extract possesses the potential for augmenting immunomodulatory activity by cellular mediated mechanism and could play a role in regulating the innate immune response., (The OMJ is Published Bimonthly and Copyrighted 2021 by the OMSB.)